Laser diode arrays and systems including structures for permitting optical power measurement therefrom

Abstract

A laser diode system permitting indirect measurement of optical power includes a laser diode which emits usable light from a front facet and spontaneously emits stray light substantially proportional to the usable light from another facet; and a light pipe disposed proximate to the laser diode which collects and waveguides only the stray light to thereby generate a stray light beam providing an indication of optical power.

What is claimed is:  
     
       1. A laser diode apparatus, comprising: 
       a laser diode which emits light in a first direction from a front facet;  
       a heatsink electrode electrically coupled to a bottom facet of the laser diode;  
       an electrode electrically coupled to a top facet of the laser diode; and  
       an isolator disposed between the heatsink electrode and the electrode, the isolator including a light pipe collecting spontaneous emissions from at least one of a rear, a left side, and a right side facet and waveguiding the collected spontaneous emissions in a second direction opposite to the first direction.  
     
     
       2. The laser diode apparatus as recited in claim  1 , wherein the laser diode comprises a laser diode bar. 
     
     
       3. The laser diode apparatus as recited in claim  1 , wherein the light pipe comprises transparent material. 
     
     
       4. The laser diode apparatus as recited in claim  3 , wherein the isolator comprises a non-conducting material. 
     
     
       5. The laser diode apparatus as recited in claim  1 , wherein the laser diode, the heatsink electrode, the electrode, and the isolator define a laser diode unit, and wherein the laser diode apparatus comprises a plurality of the laser diode units. 
     
     
       6. A laser diode system permitting indirect measurement of optical power, comprising: 
       a laser diode which emits light in first direction from a front facet;  
       a heatsink electrode electrically coupled to a bottom facet of the laser diode;  
       an electrode electrically coupled to a top facet of the laser diode;  
       an isolator disposed between the heatsink electrode and the electrode; and  
       a structural element including a light pipe collecting stray light different from but proportional to a usable component of the light and waveguiding the stray light in a second direction opposite to the first direction to thereby generate a stray light beam providing an indication of optical power.  
     
     
       7. The laser diode system as recited in claim  6 , wherein the structural element comprises a side plate. 
     
     
       8. The laser diode system as recited in claim  7 , further comprising a lens attached proximate to the front facet of the laser diode, wherein the stray light is substantially equal to the difference between the light and the usable component of the light, and wherein the side plate is optically coupled to receive the stray light but not to receive the usable component of the light from the lens. 
     
     
       9. The laser diode system as recited in claim  7 , wherein the stray light corresponds to spontaneous emissions from one of a left side and a right side facet of the laser diode. 
     
     
       10. The laser diode system as recited in claim  7 , further comprising a secondary light pipe disposed between the laser diode and the isolator, the secondary light pipe receiving stray light including spontaneous emissions from one of a rear facet, a right side facet and a left side facet of the laser diode and waveguiding the stray light to the side plate. 
     
     
       11. The laser diode system as recited in claim  7 , wherein the light pipe comprises an optical fiber. 
     
     
       12. The laser diode system as recited in claim  6 , wherein the laser diode, the heatsink electrode, the electrode and the isolator define a laser diode unit, wherein the laser diode system comprises a plurality of laser diode units, and wherein the structural element comprises a side plate operatively coupled to the laser diode units. 
     
     
       13. The laser diode system as recited in claim  12 , wherein the side plate further comprises a plurality of optical fibers, each of the optical fibers being optically coupled to a respective one of the laser diode units. 
     
     
       14. The laser diode system as recited in claim  13 , further comprising a detector array which indirectly measures optical power of the laser diode units, wherein each of the optical fibers generates an output beam responsive to the respective stray light, and wherein each of the optical fibers is coupled to a respective detector in the detector array. 
     
     
       15. The laser diode system as recited in claim  12 , wherein the side plate further comprises a transparent material which concentrates stray light from all of the laser diode units into a single stray light beam. 
     
     
       16. The laser diode system as recited in claim  12 , wherein the side plate comprises first and second side plates. 
     
     
       17. The laser diode system as recited in claim  6 , wherein the laser diode comprises a laser diode bar. 
     
     
       18. A laser diode system permitting indirect measurement of optical power, comprising: 
       a laser diode which emits usable light from a front facet and spontaneously emits stray light substantially proportional to the usable light from another facet; and  
       a light pipe, disposed proximate to the laser diode, which collects and waveguides only the stray light to thereby generate a stray light beam providing an indication of optical power.  
     
     
       19. The laser diode system as recited in claim  18 , wherein the laser diode comprises a laser diode bar. 
     
     
       20. A laser diode system permitting indirect measurement of optical power, comprising: 
       first means for emitting usable light in a first direction and for spontaneously emitting stray light substantially proportional to the usable light in a different direction; and  
       second means for collecting and waveguiding only the stray light to thereby generate a stray light beam providing an indication of optical power.